#define echopin 8
#define trigpin 10
const int buzzer = 9;
int ledM = 7;
int ledK = 6;
int ledH = 5;
long duration;
int distance;

void setup() {
  // put your setup code here, to run once:
  pinMode(trigpin, OUTPUT);
  pinMode(echopin, INPUT);
  pinMode(buzzer, OUTPUT);
  pinMode(ledM, OUTPUT);
  pinMode(ledK, OUTPUT);
  pinMode(ledH, OUTPUT);
  Serial.begin(9600);
  Serial.println("Ultrasonic Sensor HC-SRC04 Test");
  Serial.println("With Arduino Uno R3");
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(trigpin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigpin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigpin, LOW);
  duration = pulseIn(echopin, HIGH);
  distance = duration * 0.034/2;

  Serial.print("distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  if(distance < 30){
    digitalWrite(ledM, HIGH);
    digitalWrite(ledK, LOW);
    digitalWrite(ledH, LOW);
    tone(buzzer, 1000);
    delay(1000);
    noTone(buzzer);
  }
  if(distance >= 31 && distance < 60){
    digitalWrite(ledM, HIGH);
    digitalWrite(ledK, LOW);
    digitalWrite(ledH, LOW);
    tone(buzzer, 950);
    delay(1000);
    noTone(buzzer);
  }
  if(distance >= 61 && distance < 90){
    digitalWrite(ledM, HIGH);
    digitalWrite(ledK, LOW);
    digitalWrite(ledH, LOW);
    tone(buzzer, 900);
    delay(1000);
    noTone(buzzer);
  }
   if(distance >= 91 && distance < 120){
    digitalWrite(ledM, HIGH);
    digitalWrite(ledK, LOW);
    digitalWrite(ledH, LOW);
    tone(buzzer, 850);
    delay(1000);
    noTone(buzzer);
  }
  if(distance >= 121 && distance < 150){
    digitalWrite(ledM, HIGH);
    digitalWrite(ledK, LOW);
    digitalWrite(ledH, LOW);
    tone(buzzer, 800);
    delay(1000);
    noTone(buzzer);
  }
  if(distance >= 151 && distance < 180){
    digitalWrite(ledM, LOW);
    digitalWrite(ledK, HIGH);
    digitalWrite(ledH, LOW);
    tone(buzzer, 750);
    delay(1000);
    noTone(buzzer);
  }
  if(distance >= 181 && distance < 210){
    digitalWrite(ledM, LOW);
    digitalWrite(ledK, HIGH);
    digitalWrite(ledH, LOW);
    tone(buzzer, 700);
    delay(1000);
    noTone(buzzer);
  }
  if(distance >= 211 && distance < 240){
    digitalWrite(ledM, LOW);
    digitalWrite(ledK, HIGH);
    digitalWrite(ledH, LOW);
    tone(buzzer, 650);
    delay(1000);
    noTone(buzzer);
  }
  if(distance >= 241 && distance < 270){
    digitalWrite(ledM, LOW);
    digitalWrite(ledK, HIGH);
    digitalWrite(ledH, LOW);
    tone(buzzer, 600);
    delay(1000);
    noTone(buzzer);
  }
  if(distance >= 271 && distance < 300){
    digitalWrite(ledM, LOW);
    digitalWrite(ledK, LOW);
    digitalWrite(ledH, HIGH);
    tone(buzzer, 550);
    delay(1000);
    noTone(buzzer);
  }
  if(distance >= 301 && distance < 330){
    digitalWrite(ledM, LOW);
    digitalWrite(ledK, LOW);
    digitalWrite(ledH, HIGH);
    tone(buzzer, 500);
    delay(1000);
    noTone(buzzer);
  }
  if(distance >= 331 && distance < 360){
    digitalWrite(ledM, LOW);
    digitalWrite(ledK, LOW);
    digitalWrite(ledH, HIGH);
    tone(buzzer, 450);
    delay(1000);
    noTone(buzzer);
  }
  if(distance >= 361 && distance < 400){
    digitalWrite(ledM, LOW);
    digitalWrite(ledK, LOW);
    digitalWrite(ledH, HIGH);
    tone(buzzer, 400);
    delay(1000);
    noTone(buzzer);
  }
}